Microarray Analysis of Lymphatic Tissue Reveals Stage-Specific, Gene-Expression Signatures in HIV-1 Infection

Untreated HIV-1 infection progresses through acute and asymptomatic stages to AIDS. While each of the three stages has well-known clinical, virologic and immunological characteristics, much less is known of the molecular mechanisms underlying each stage. Here we report lymphatic tissue microarray analyses revealing for the first time stage-specific patterns of gene expression during HIV-1 infection. We show that while there is a common set of key genes with altered expression throughout all stages, each stage has a unique gene-expression signature. The acute stage is most notably characterized by increased expression of hundreds of genes involved in immune activation, innate immune defenses (e.g.MDA-5, TLR-7 and -8, PKR, APOBEC3B, 3F, 3G), adaptive immunity, and in the pro-apoptotic Fas-Fas-L pathway. Yet, quite strikingly, the expression of nearly all acute-stage genes return to baseline levels in the asymptomatic stage, accompanying partial control of infection. In the AIDS stage, decreased expression of numerous genes involved in T cell signaling identifies genes contributing to T cell dysfunction. These common and stage-specific, gene-expression signatures provide new insights into the molecular mechanisms underlying the host response and the slow, natural course of HIV-1 infection. A total of 52 patients were analyzed: 10 patients unaffected, 18 patients with asymptomatic stages of AIDs, 16 patients with acute stages of AIDs, and 8 patients with AIDs.